GetChangeDescriptionFromGitiles followup: future todo for no gitiles.

gerrit_util.py

 # Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
 Utilities for requesting information for a gerrit server via https.
 
 https://gerrit-review.googlesource.com/Documentation/rest-api.html
 """
 
@@ skipping 473 matching lines @@
 
 
 def GetChangeDescriptionFromGitiles(url, revision):
   """Query Gitiles for actual commit message for a given url and ref.
 
   url must be obtained from call to GetChangeDetail for a specific
   revision (patchset) under 'fetch' key.
   """
   parsed = urlparse.urlparse(url)
   path = '%s/+/%s?format=json' % (parsed.path, revision)
+  # Note: Gerrit instances that Chrome infrastructure uses thus far have all
+  # enabled Gitiles, which allowes us to execute this call. This isn't true for
+  # all Gerrit instances out there. Thus, if line below fails, consider adding a
+  # fallback onto actually fetching ref from remote using pure git.
   return ReadHttpJsonResponse(CreateHttpConn(parsed.netloc, path))['message']
 
 
 def GetChangeCurrentRevision(host, change):
   """Get information about the latest revision for a given change."""
   return QueryChanges(host, {}, change, o_params=('CURRENT_REVISION',))
 
 
 def GetChangeRevisions(host, change):
   """Get information about all revisions associated with a change."""
@@ skipping 142 matching lines @@
         username = review.get('email', jmsg.get('name', ''))
         raise GerritError(200, 'Unable to set %s label for user "%s"'
                        ' on change %s.' % (label, username, change))
   jmsg = GetChangeCurrentRevision(host, change)
   if not jmsg:
     raise GerritError(
         200, 'Could not get review information for change "%s"' % change)
   elif jmsg[0]['current_revision'] != revision:
     raise GerritError(200, 'While resetting labels on change "%s", '
                    'a new patchset was uploaded.' % change)